It is an object of the invention to provide an electric railway system in which the acceleration, running and braking of a locomotive are controlled remotely and automatically from the trackside by the use of trackside power supplies and trackside electric braking loads, and to provide a locomotive (which is to be understood as including any motorised rail vehicle) equipped with a suitable electric motor and suitable associated on-board circuitry.
In particular, it is an object of the invention to provide a locomotive having a traction motor which includes both a series field winding and a shunt, or separately-excited, field winding and in which the circuit connections of these windings are automatically altered as between driving and electric braking conditions, with a view to producing favourable performance in both conditions.